Patent GB-922721-A (GB)
Title: Improved strip film and sound projector for reproducing and projecting from such film
Inventor: SCHWARTZ MORRIS
IPC: G03B31/06
Filed: 1959-12-09
Abstract: 922,721. Sound and picture apparatus. KALART CO. Inc. Dec. 9, 1959, No. 41855/59. Class 40 (2). [Also in Group XX] In a sound and still picture projector a film as described and claimed in divisional Specification 922,722 and having sound and picture areas thereon is held stationary while the sound is played and means are provided for resetting the playback means for a subsequent operation. In one embodiment, Figs. 1, 2 and 4, the film 210 is transported vertically and the sound track comprises transverse parallel optical tracks 218 which are scanned by a cylindrical element 226 containing a light source 236 and a pair of diametrically oppositely placed lenses 238, 240 whereby a slit image of the light source 236 sequentially scans the tracks. The cylindrical element 226 is raised during the scanning process by means of a screw-thread 250 thereon which is engaged by a grooved driving wheel 252 when a solenoid 276 is operated to cause tensioning of a moving drive belt 266, and a bearing member 256, carrying wheel 252, to be thereby rotated about a pin 58. Prior to the above operation the film has been advanced to its correct position by the operation of a solenoid 304 which effects clutching engagement between a motor drive shaft 278 and a wheel 300. When the cylindrical element has reached the upper point of its traverse, solenoid 276 is de-energized, wheel 252 is thereby withdrawn and the cylindrical element 226 falls to its initial position. In an alternative embodiment, Figs. 6, 11, 15 and 19, the film 110 is transported horizontally and the sound track comprises longitudinally parallel tracks which are scanned by a drum 42 mounted on a screw-threaded shaft which, when a scanning operation takes place, is engaged by the two halves of a split nut 23 which close together by spring tension when a solenoid 23d is de-energized. At the end of a scanning sequence, a 25-cycle note on the sound track may be provided to operate a relay to temporarily energize the split nut solenoid 23d to release the cylinder 12 so that it drops to its initial position. At the same time another solenoid 175 is temporarily energized to effect a further transportation of the film. Operation of this solenoid moves a notched end 172 of a lever, pivoted at a fixed point 171, out of engagement with a member 163b pivoted on a block 162 mounted on a shaft 161. The removal of the notched end 172 permits the member 163b to drop into the path of a pin 168 on a flywheel 115 so that a drive is established from the motor 22 to the film transport sockets 2, 2<SP>1</SP>. At the completion of one revolution of the flywheel, solenoid 175 has become deenergized and member 163b is lifted by a spring 173 back into the notch 172 out of engagement with the pin 168. At this point the split nut 23 closes in the absence of solenoid current and scanning of the next sound track takes place. The initiation of the automatic cycle may be effected by a notch in the film in place of the 25-cycle note on the sound track. In this case the raising of the cylinder 12 causes a cam surface to move a roller along the edge of the film until it drops into the notch and completes the solenoid circuits. When the scanning cylinder 12 traverses the film while supported in the sound gate guide 3 a toroidal mirror 40 and a cylindrically surfaced mirror 41 are carried upwardly with the cylinder 12 and are so shaped and arranged that the light beam is continuously directed on to the photo-electric cell 42.